Patent GB-581785-A (GB)
Title: Process for imparting a transparent or organdie effect to fibres or fabrics made therefrom
IPC: D06Q1/02
Filed: 1943-10-25
Abstract: Natural or artificial fibres or fabrics thereof are given a transparent or organdi effect and their tendency to curl and shrink is reduced by impregnating them with a solution or emulsion containing at least 5 per cent of an organic-solvent-soluble, substantially water-insoluble alkylated urea formaldehyde resin or alkylated amino-triazine-formaldehyde resin, and drying and fixing the resin on the materials by heat.  The resin is applied to the material in solution in an organic solvent such as an alcohol. Natural or artificial cellulosic fibres such as cotton or regenerated cellulose, silk, wool or superpolyamide and polyurethane fibres may be treated according to the invention. Impregnation is effected on the foulard, or by brushing, or by printing or stencilling when local figured effects are obtained. Decorative figured effects are produced by printing the dyed or colour printed material with the resin solution, or by pigment printing in combination with printing with the resin solution. Dyestuffs such as Sudan Red may be added to the resin solution or the resin printed material may be subsequently dyed with acid dyestuffs; or with a mixture of acid and substantive dyestuffs when a two colour effect is obtained.  The resins are condensation products of, e.g. urea or melamine with formaldehyde which have been condensed in the presence of alcohols such as methyl or butyl alcohol, or a polyhydric alcohol.  Plasticisers such as tricresyl-phosphate or diethyl phthalate, may be added to the resin solution, or to the mixture of resin components before or during condensation.  Thickening agents such as nitrocellulose may be added to the resin solution.  Examples of the preparation of the resin are given in which (A) urea-formaldehyde butyl ether resin is prepared by refluxing a mixture of urea and a solution of paraformaldehyde and hexamethylenetetramine in N-butanol to which formic acid is subsequently added, and the water of reaction distilled off.  (B) Melamine-formaldehyde-butyl-ether-resin is prepared by heating a mixture of hexamethylol melamine, N-butanol, and formic acid. Numerous examples of the impregnation and local printing of fabrics with butanol solutions of the resins prepared as above are given in which: (3) artificial silk georgette is printed with resin solution A thickened with nitrocellulose and amyl acetate, dried, and heated at 120 DEG  C.  The unprinted ground is creped by treatment in a warm soap bath.  (6) Mercerised cotton muslin is printed with resin solution A, dried, heated at 140 DEG  C., immersed in caustic soda solution and washed to produce transparent figurings on a mercerised ground.  (7) Mercerised cotton muslin is printed as in example 6 and top-printed to a different pattern with a gum arabic solution and finally treated in a caustic soda bath.  (12) Mercerised bleached cotton voile is printed with resin solution (b) thickened with nitrocellulose and amyl acetate, heated at 130 DEG  C. and topprinted with a thick caustic soda solution whereby the alkali printed parts shrink. (15) Viscose muslin is impregnated with a reserve containing acetyl cellulose, phenol, acetone and titanium white, and then impregnated with resin solution (A), dried, and heated at 110 DEG  C. (19) Viscose muslin is impregnated with an emulsion of resin solution (A) in an aqueous solution of ethyl cellulose containing butanol and to which a solution of dimethyl-benzyllauryl ammonium chloride in dilute ethyl alcohol is added.  In the examples it is also specified that tartaric acid and dimethyl glycol phthalate may be added to the resin solutions while specified dispersants are ethyl alcohol, amyl acetate, ethyl acetate and toluene. Specifications 537,971, 543,256 and 543,860 are referred to.  The Specification as open to inspection under Sect. 91 comprises also the use of melamine-formaldehyde methyl ether resin which is prepared by refluxing hexamethylol melamine in methyl alcohol in the presence of concentrated sulphuric acid, and the clear solution neutralised with sodium carbonate.  This subject-matter does not appear in the Specification as accepted.